Evaluation of Total Corneal Thickness and Corneal Layers With Spectral-Domain Optical Coherence Tomography

PURPOSE: To evaluate total corneal thickness and corneal layers in healthy young adults using spectral-domain optical coherence tomography and to describe its repeatability and reproducibility. METHODS: Eighty-six eyes from 86 healthy volunteers were prospectively and consecutively enrolled. Manual measurements of central corneal thickness (CCT) and central thickness of epithelium, Bowman's layer, stroma, and the Descemet-endothelium complex were performed using Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). To assess the reliability of the repeated measurements, intraclass correlation coefficients and coefficients of variation were used. RESULTS: Mean CCT, epithelium, Bowman's layer, stroma, and Descemet-endothelium values were 555.50 +/- 29.64, 54.60 +/- 4.25, 16.70 +/- 1.73, 467.51 +/- 28.91, and 16.74 +/- 1.66 mu m, respectively. The intraclass correlation coefficients ranged from 0.746 (Bowman's layer) to 0.999 (CCT and stroma) and from 0.483 (Bowman's layer) to 0.995 (CCT) and 0.998 (stroma) for intraobserver repeatability and interobserver reproducibility, respectively. The measurements showed coefficients of variation lower than 11% in all cases. CONCLUSIONS: This study establishes a normal database for corneal thickness and all its layers in healthy young adults with spectral-domain optical coherence tomography. This device exhibited a high degree of intraobserver repeatability and interobserver reproducibility for all regions except Bowman's layer.